This application claims priority to an application entitled xe2x80x9cApparatus and Method for Switching Service Class According to Generated Heat in a GPRS Terminalxe2x80x9d filed in the Korean Industrial Property Office on Sep. 29, 2000 and assigned Serial No. 2000-57329, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates generally to a GPRS (General Packet Radio Service) system, and in particular, to an apparatus and method for switching a service class according to the heat generated by a specific element in a GPRS terminal.
2. Description of the Related Art
In general, xe2x80x9cGPRSxe2x80x9d refers to a radio packet data service provided in a European-style GSM (Global System for Mobile communication) system, and corresponds to the HDR (High Data Rate) technique developed by Qualcomm, USA. The GPRS system increases a data rate per GSM channel from 9600 bps (bits per second) to 14400 bps by performing packet switching in a GSM network, and can support high-speed packet switching of up to 14.4-115 Kbps in the existing GSM network environment through a data compression technique. That is, the GPRS system, facilitating the expansion of a data network to the mobile communication network, provides a GSM packet data service, manages packet mobility and billing processes using GSM network equipment such as HLR (Home Location Register) and VLR (Visitor Location Register), and also provides paging and SMS (Short Message Service) services to the voice service.
In a GPRS terminal, a GPRS service class is classified into 12 service classes according to the duration of the time slots as occupied per frame. That is, the GPRS terminal can occupy a maximum of 5 time slots per frame, including time slots for transmission (TX) and time slots for reception (RX). An increase in the number of the occupied time slots causes an increase in the entire duration of the occupied time slots, thus enabling the GPRS terminal to transmit and receive an increased amount of data. The 12 service classes are again classified into first and second classes, such as a high class and a low class according to relative duration of the time slots.
When the GSM GPRS terminal supporting high-speed data communication is provided with the high-class GPRS service where transmission power is set high and the duration of the time slots is set long, specific elements such as a power supply IC (Integrated Circuit), a power amplifier module and a processor are subject to heat generation due to the increased duration of the time slots, thereby causing deterioration of the QoS (Quality of Service) and damage to the elements in the RF transceiver. In the prior art, switching between service classes is not readily available to alleviate the heat generation problem.
It is, therefore, an object of the present invention to provide an apparatus and method for switching a GPRS service class in response to the heat generated by specific elements in a GPRS terminal during a GPRS mode of operation.
To achieve the above and other objects, there is provided an apparatus for switching a GPRS service class in a GPRS terminal. A temperature sensor measures a temperature of at least one specific element in the GPRS terminal during a GPRS mode of operation. An analog-to-digital (A/D) converter converts an analog value of the temperature measured by the temperature sensor to a digital value. A limit data register stores a critical temperature of the specific element for the GPRS service class. A controller compares the measured temperature from the temperature sensor with the critical temperature stored in the limit data register, and switches the GPRS service class to a low class, when the measured temperature is greater than or equal to the critical temperature. The controller maintains the present GPRS service class when the measured temperature is less than the critical temperature. Further, the controller switches the GPRS service class from the low class back to the high class, when the measured temperature becomes less than the critical temperature during the low-class GPRS service.